[lua] Add access to user data properties in Sprite object (aseprite/api#88)

This is a basic implementation where we can only access basic
properties (not maps or vectors yet).

src/app/CMakeLists.txt

@@ -191,6 +191,7 @@ if(ENABLE_SCRIPTING)
     script/plugin_class.cpp
     script/point_class.cpp
     script/preferences_object.cpp
+    script/properties_class.cpp
     script/range_class.cpp
     script/rectangle_class.cpp
     script/security.cpp

src/app/script/engine.cpp

@@ -176,6 +176,7 @@ void register_palette_class(lua_State* L);
 void register_palettes_class(lua_State* L);
 void register_plugin_class(lua_State* L);
 void register_point_class(lua_State* L);
+void register_properties_class(lua_State* L);
 void register_range_class(lua_State* L);
 void register_rect_class(lua_State* L);
 void register_selection_class(lua_State* L);
@@ -454,6 +455,7 @@ Engine::Engine()
   register_palettes_class(L);
   register_plugin_class(L);
   register_point_class(L);
+  register_properties_class(L);
   register_range_class(L);
   register_rect_class(L);
   register_selection_class(L);

src/app/script/engine.h

@@ -150,6 +150,7 @@ namespace app {
   void push_layers(lua_State* L, const doc::ObjectIds& layers);
   void push_palette(lua_State* L, doc::Palette* palette);
   void push_plugin(lua_State* L, Extension* ext);
+  void push_properties(lua_State* L, doc::WithUserData* userData);
   void push_sprite_cel(lua_State* L, doc::Cel* cel);
   void push_sprite_events(lua_State* L, doc::Sprite* sprite);
   void push_sprite_frame(lua_State* L, doc::Sprite* sprite, doc::frame_t frame);
@@ -166,7 +167,6 @@ namespace app {
   void push_tileset_image(lua_State* L, doc::Tileset* tileset, doc::Image* image);
   void push_tilesets(lua_State* L, doc::Tilesets* tilesets);
   void push_tool(lua_State* L, app::tools::Tool* tool);
-  void push_userdata(lua_State* L, doc::WithUserData* userData);
   void push_version(lua_State* L, const base::Version& ver);
 
   gfx::Point convert_args_into_point(lua_State* L, int index);

src/app/script/properties_class.cpp

@@ -0,0 +1,128 @@
+// Aseprite
+// Copyright (C) 2022  Igara Studio S.A.
+//
+// This program is distributed under the terms of
+// the End-User License Agreement for Aseprite.
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "app/script/docobj.h"
+#include "app/script/engine.h"
+#include "app/script/luacpp.h"
+#include "app/script/values.h"
+#include "doc/with_user_data.h"
+
+#include <cstring>
+
+namespace app {
+namespace script {
+
+namespace {
+
+struct Properties {
+  doc::ObjectId id = 0;
+  Properties(doc::ObjectId id) : id(id) { }
+};
+
+int Properties_index(lua_State* L)
+{
+  auto propObj = get_obj<Properties>(L, 1);
+  const char* field = lua_tostring(L, 2);
+  if (!field)
+    return luaL_error(L, "field in 'properties.field' must be a string");
+
+  auto obj = static_cast<doc::WithUserData*>(get_object(propObj->id));
+  if (!obj)
+    return luaL_error(L, "the object with these properties was destroyed");
+
+  auto& properties = obj->userData().properties();
+  auto it = properties.find(field);
+  if (it != properties.end()) {
+    push_value_to_lua(L, (*it).second);
+  }
+  else {
+    lua_pushnil(L);
+  }
+  return 1;
+}
+
+int Properties_newindex(lua_State* L)
+{
+  auto propObj = get_obj<Properties>(L, 1);
+  const char* field = lua_tostring(L, 2);
+  if (!field)
+    return luaL_error(L, "field in 'properties.field' must be a string");
+
+  auto obj = static_cast<doc::WithUserData*>(get_object(propObj->id));
+  if (!obj)
+    return luaL_error(L, "the object with these properties was destroyed");
+
+  auto& properties = obj->userData().properties();
+
+  // TODO add undo information
+  switch (lua_type(L, 3)) {
+
+    case LUA_TNONE:
+    case LUA_TNIL:
+    default: {
+      // Just erase the property
+      auto it = properties.find(field);
+      if (it != properties.end())
+        properties.erase(it);
+      break;
+    }
+
+    case LUA_TBOOLEAN:
+      properties[field] = (lua_toboolean(L, 3) ? true: false);
+      break;
+
+    case LUA_TNUMBER:
+      if (lua_isinteger(L, 3))
+        properties[field] = lua_tointeger(L, 3);
+      else {
+        properties[field] = doc::UserData::Fixed{
+          fixmath::ftofix(lua_tonumber(L, 3))
+        };
+      }
+      break;
+
+    case LUA_TSTRING:
+      properties[field] = lua_tostring(L, 3);
+      break;
+
+    case LUA_TTABLE:
+      // TODO convert a full table into properties recursively
+      break;
+
+    case LUA_TUSERDATA:
+      // TODO convert table-like objects (Size, Point, Rectangle, etc.)
+      break;
+
+  }
+  return 1;
+}
+
+const luaL_Reg Properties_methods[] = {
+  { "__index", Properties_index },
+  { "__newindex", Properties_newindex },
+  { nullptr, nullptr }
+};
+
+} // anonymous namespace
+
+DEF_MTNAME(Properties);
+
+void register_properties_class(lua_State* L)
+{
+  REG_CLASS(L, Properties);
+}
+
+void push_properties(lua_State* L, doc::WithUserData* userData)
+{
+  push_obj<Properties>(L, userData->id());
+}
+
+} // namespace script
+} // namespace app

src/app/script/sprite_class.cpp

@@ -882,6 +882,7 @@ const Property Sprite_properties[] = {
   { "gridBounds", Sprite_get_gridBounds, Sprite_set_gridBounds },
   { "color", UserData_get_color<Sprite>, UserData_set_color<Sprite> },
   { "data", UserData_get_text<Sprite>, UserData_set_text<Sprite> },
+  { "properties", UserData_get_properties<Sprite>, nullptr },
   { "pixelRatio", Sprite_get_pixelRatio, Sprite_set_pixelRatio },
   { "events", Sprite_get_events, nullptr },
   { nullptr, nullptr, nullptr }

src/app/script/userdata.h

@@ -51,6 +51,13 @@ int UserData_get_color(lua_State* L) {
   return 1;
 }
 
+template<typename T>
+int UserData_get_properties(lua_State* L) {
+  auto obj = get_docobj<T>(L, 1);
+  push_properties(L, get_WithUserData<T>(obj));
+  return 1;
+}
+
 template<typename T>
 int UserData_set_text(lua_State* L) {
   auto obj = get_docobj<T>(L, 1);

src/app/script/values.cpp

@@ -16,6 +16,7 @@
 #include "doc/remap.h"
 
 #include <any>
+#include <variant>
 
 namespace app {
 namespace script {
@@ -39,9 +40,21 @@ bool get_value_from_lua(lua_State* L, int index) {
 // int
 
 template<>
-void push_value_to_lua(lua_State* L, const int& value) {
-  lua_pushinteger(L, value);
-}
+void push_value_to_lua(lua_State* L, const int8_t& value) { lua_pushinteger(L, value); }
+template<>
+void push_value_to_lua(lua_State* L, const int16_t& value) { lua_pushinteger(L, value); }
+template<>
+void push_value_to_lua(lua_State* L, const int32_t& value) { lua_pushinteger(L, value); }
+template<>
+void push_value_to_lua(lua_State* L, const int64_t& value) { lua_pushinteger(L, value); }
+template<>
+void push_value_to_lua(lua_State* L, const uint8_t& value) { lua_pushinteger(L, value); }
+template<>
+void push_value_to_lua(lua_State* L, const uint16_t& value) { lua_pushinteger(L, value); }
+template<>
+void push_value_to_lua(lua_State* L, const uint32_t& value) { lua_pushinteger(L, value); }
+template<>
+void push_value_to_lua(lua_State* L, const uint64_t& value) { lua_pushinteger(L, value); }
 
 template<>
 int get_value_from_lua(lua_State* L, int index) {
@@ -61,6 +74,14 @@ double get_value_from_lua(lua_State* L, int index) {
   return lua_tonumber(L, index);
 }
 
+// ----------------------------------------------------------------------
+// fixed
+
+template<>
+void push_value_to_lua(lua_State* L, const doc::UserData::Fixed& value) {
+  lua_pushnumber(L, fixmath::fixtof(value.value));
+}
+
 // ----------------------------------------------------------------------
 // std::string
 
@@ -193,10 +214,12 @@ app::tools::InkType get_value_from_lua(lua_State* L, int index) {
 // ----------------------------------------------------------------------
 // doc::tile_t
 
+#if 0 // doc::tile_t matches uint32_t, and we have the uint32_t version already defined
 template<>
 void push_value_to_lua(lua_State* L, const doc::tile_t& value) {
   lua_pushinteger(L, value);
 }
+#endif
 
 template<>
 doc::tile_t get_value_from_lua(lua_State* L, int index) {
@@ -251,5 +274,23 @@ FOR_ENUM(filters::HueSaturationFilter::Mode)
 FOR_ENUM(filters::TiledMode)
 FOR_ENUM(render::OnionskinPosition)
 
+// ----------------------------------------------------------------------
+// UserData::Properties / VariantStruct
+
+template<>
+void push_value_to_lua(lua_State* L, const doc::UserData::Properties& value) {
+  // TODO convert a Properties map into a Lua table
+}
+
+template<>
+void push_value_to_lua(lua_State* L, const doc::UserData::Vector& value) {
+  // TODO convert a Vector into a Lua table
+}
+
+template<>
+void push_value_to_lua(lua_State* L, const doc::UserData::Variant& value) {
+  std::visit([L](auto&& v){ push_value_to_lua(L, v); }, value);
+}
+
 } // namespace script
 } // namespace app

tests/scripts/userdata.lua

@@ -0,0 +1,24 @@
+-- Copyright (C) 2022  Igara Studio S.A.
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local spr = Sprite(1, 1)
+
+  spr.properties.a = true
+  spr.properties.b = 1
+  spr.properties.c = "hi"
+  spr.properties.d = 2.3
+  assert(spr.properties.a == true)
+  assert(spr.properties.b == 1)
+  assert(spr.properties.c == "hi")
+  -- TODO we don't have too much precision saving fixed points in properties
+  assert(math.abs(spr.properties.d - 2.3) < 0.00001)
+
+  spr.properties.a = false
+  assert(spr.properties.a == false)
+
+  spr.properties.b = nil
+  assert(spr.properties.b == nil)
+end